Disk drives are widely used in computers, consumer electronics and data processing systems for storing information in digital form. A disk drive typically includes one or more storage disks and one or more sliders. Each slider includes a read/write head that transfers information to and from the storage disk. Rotation of the storage disk causes the slider to ride on an air bearing so that the read/write head is at a distance from the storage disk that is commonly referred to as a “head-to-disk spacing” or “fly height”.
A number of factors can influence the fly height of a slider. For example, altitude can influence the fly height of certain sliders. Further, during a write operation, current flow in the write element of the read/write head generates heat and a temperature increase in and around the read/write head. This temperature increase causes thermal expansion of a portion of the slider toward the storage disk, known as “pole tip protrusion” or PTP. If the pole tip protrusion is too extensive, the slider can unintentionally contact the storage disk, causing off-track writing, damage to the slider, damage to the storage disk and/or a permanent loss of data.
Many attempts have been made to design a slider having certain specific desirable characteristics during operation of the disk drive. These desirable characteristics for a slider include: (i) no significant fly height loss due to altitude changes; (ii) quick takeoffs from a landed position on the storage disk; (iii) relative fly height insensitivity to pole tip protrusion; and (iv) self-cleaning flow field to avoid contamination build-up of read/write head.
Previous attempts to provide these varied characteristics have accomplished strong results in some areas, but mixed results across all characteristics.